Width of Flux Peaks in Asymmetry-Induced Transport in a Non-Neutral Plasma

Abstract

This summer we studied asymmetry-induced radial transport with non-neutral plasmas in a modified Malmberg-Penning trap. In short, asymmetry-induced transport is the radial movement of plasma particles by applied voltages on the container walls. Although asymmetry-induced radial transport in non-neutral plasmas is well known and reproducible, a firm connection between theory and experiment is missing. Experimental data needs to be characterized and understood in relation to experimental variables. To assist in this endeavor, we analyzed several graphs of experimental data conducted in the Plasma Lab at Occidental. Specifically we analyzed the width of peaks seen on graphs of radial flux vs. asymmetry frequency. Our analysis indicates: where Δf is the width of the peak at half of the max, ф is the center wire bias in volts, B is the magnetic field in gauss, and r is the radius in centimeters. In an attempt to further explain radial transport, we hypothesized a general equation designed to fit all of the curves seen in the experimental data: where Γ is the radial Flux, f is the asymmetry frequency, and A through F are unknown parameters which relate to experimental variables. This equation fits the general curves fairly accurately if the Gaussian portion of Γ is dominant. Additionally, we found that Δf and D are related by: